Synthesis and characterization of yttrium oxide (Y2O3) deposits

The synthesis of yttrium oxide (Y2O3) was accomplished by evaporating elemental yttrium in the presence of oxygen. High-rate physical vapor deposition was employed using both the reactive evaporation (RE) and activated reactive evaporation (ARE) processes. The ARE process resulted in a higher Y2O3/Y ratio for two reasons: more complete reaction and fewer globules of Y being ejected from the molten pool and landing on the deposit surface. The microstructure and mechanical properties of the deposit produced varied with the deposition temperature in accordance with the structural zone model of Movchan and Demchishin. Over a deposition temperature range of 1210 to 7210C, the surface energy, as determined by Hertzian fracture, varied from 645 to 515 erg/cm2, and the microhardness varied from 320 to 502 kg/mm2